Broken Link Checker <= 1.11.16 - Authenticated (Admin+) PHAR Deserialization

The Broken Link Checker plugin for WordPress is vulnerable to deserialization of untrusted input via the '$log_file' value in versions up to, and including 1.11.16. This makes it possible for authenticated attackers with administrative privileges and above to call files using a PHAR wrapper that will deserialize the data and call arbitrary PHP Objects that can be used to perform a variety of malicious actions granted a POP chain is also present. It also requires that the attacker is successful in uploading a file with the serialized payload.

An attacker needs Admin access first, so the firewall sees the attempt as traffic from a logged-in account: WordSec's web application firewall inspects request payloads before WordPress loads them. Classes like this one can leave something behind, so the staged malware scanner is the second half: it looks for dropped files and modified code rather than for the request that created them. None of that substitutes for the fix: Broken Link Checker 1.11.17 closes this, and updating the plugin is the step that ends it.

• Firewall
• Scanner
• Alerts